1. Field of the Invention
The present invention relates generally to the field of load binders used to secure cargo for transport. Particularly, the present invention relates to a locking structure to secure the lever handle of a load binder. More particularly, the present invention relates to a locking structure to secure spring-loaded over-center lever type load binders and to prevent injury or damage as a result of their premature release.
2. Description of the Prior Art
Spring-loaded, over-center load binders are conventionally used to secure cargo in the transportation industry, for example on flatbed trucks, freight trains, cargo ships, and the like. The load binder employs a lever, which is typically comprised of two or more connected components that rotate between an open and closed position about an axis. The components generally include a handle and a receiving cradle. The lever is used to place tension on a hold-down element surrounding the cargo, such as a chain or strap, to hold the cargo in place.
To secure the cargo, the handle of the lever is moved from an open position, where the hold down element is slack, to a closed position, where the hold down element is taut. The hold-down element is pulled taut when the handle has passed the over-center position. When the load binder is closed, the lever components are usually parallel and one may fit inside the other. Pressure on a load binder is released as the operator manually moves the lever handle from the closed position towards the over-center position. While the operator is handling the binder or when the operator is within the vicinity of one or more binders under pressure, premature release of the binder may expose the operator or others to serious personal injury or even death. Premature release may also cause damage to the cargo or other property.
Means to lock load binders are well known in the art. Most load binders available today have some method of securing the lever handle in place after the hold-down element has been pulled taut around the cargo. These methods may include the use of removable locks and locking parts, such as keys or pins. Most have been designed with the aim of preventing premature release of the tension on the hold-down element.
U.S. Pat. No. 3,954,252 discloses a load binder that is secured by attaching a locking part, such as a pin or padlock, to a component of the binder. In this invention, a receiving cradle is comprised of two flanges with aligned circular apertures designed to receive a pin, padlock, or other locking part. The apertures are situated so as to be on either side of the lever handle when it is in a fully closed position. When the handle is closed, the locking part slides through the holes over the handle, preventing it from opening.
There are several disadvantages to using a padlock or straight pin to secure a load binder. For example, when using a padlock, the operator must keep track of a key or remember a combination. As several binders are typically used to secure a load, the padlocks would all have to be keyed or coded the same to prevent confusion. A key is easily bent, lost, or misplaced and thus is not ideal to secure a load binder on its own or in conjunction with a padlock. Where the locking part is a pin, there is a high likelihood the pin may slip out of the apertures upon jarring of the binder caused by moving of the transport vehicle. Using a wire ring or other similar object to secure the pin would further complicate the process. This requires extra steps to properly secure the binder handle and such objects are easily lost.
U.S. Pat. Nos. 4,683,728 and 4,693,097 disclose portable locking devices that may be attached to a binder lock to secure the lever handle with a padlock. U.S. Pat. No. 4,683,728 is comprised of a tube-like component with a flange. With the load binder tight and the lever handle in a fully closed position, the operator slides the invention over the handle with the flange facing the hold-down element, ideally a chain. A padlock is placed through a hole in the flange, the closest link of the chain, and then locked. In this manner, the lever handle is secured and the hold-down element is prevented from slipping.
U.S. Pat. No. 4,693,097 is comprised of a pin affixed centrally to and projecting from the lock""s main wall. This projection is flanked by two side-walls. There is a locking chain affixed to one of the sidewalls. The other side-wall has an extension with an opening. When the load binder is tight and the lever handle is in a closed position, the pin fits through the hold-down element, ideally a chain. The locking chain is wrapped around the handle and secured to the opposite side-wall by a padlock placed through the chain and the opening in that side-wall. While these inventions may secure the binder lock, they are inferior to the simplicity and safety of the present invention. A portable lock is most easily attached using two handsxe2x80x94one to hold the device on the binder and the other to attach the padlock to it. For safety reasons, the operator ideally should have one hand on the closed lever handle while securing the binder to prevent accidental release. He or she is forced to choose between safety and ease of attachment.
U.S. Pat. No. 5,775,673 discloses a binder tool that can be used to lock a lever handle in addition to its primary purpose of preventing injury to the operator. This tool is attached to the hold down element by a sliding part and moved towards and under the closed lever handle when the operator desires to open it. It is comprised of a short portion to receive the lever handle, flanges with holes to attach it to the sliding part with a pin, and then a long handle extending upwards from the pin. The tool rotates on the pin and when the operator pulls it towards his or her body, the lever handle is pushed away from the operator as the pressure is released and the lever opens. Although the disclosure suggests that this tool can be designed to fit down over the lever handle and lock it in a variety of ways, no particular method is specified. While this tool may be useful in helping to safely move a load binder lever from the closed to open position, it does not adequately address how to secure the binder when it is in a closed position.
U.S. Pat. Nos. 4,062,206 and 3,974,668 disclose a means of locking a load binder with a key or Allen Wrench. In U.S. Pat. No. 4,062,206, when the hold-down element is taut and the lever is in the closed position, the handle engages a hook and is subsequently locked to the hook with a removable key. U.S. Pat. No. 3,974,668 utilizes a spring-loaded latch to secure the lever handle of a load binder. When the handle is securely latched, the mechanism is locked and can be released with the use of a conventional key or an Allen Wrench. These inventions, while useful, are inferior to the present invention in that they require a detached key or tool to release a locked load binder. Keys and tools are easily misplaced, broken, or stuck. In addition, where load binders are used outdoors the majority of the time, the lock itself may become rusty and unmanageable.
U.S. Pat. No. 3,842,426 discloses a load binder secured by means of a latching system. As the lever handle is pushed down to the closed position, the rotating end of the handle component pops over a raised portion of the receiving component and into a groove. Once secured in the groove, the lever is supposed to be held in place. This invention does not adequately assure the safety of the operator. Without a secure locking structure, even a small amount of force may cause the lever handle to fly open. The disclosure suggests using another method of securing the handle, such as tying wire or rope around the hold-down element and handle in the closed position. This method is impractical and risky, where the operator would need two hands to tie down the handle. This would necessitate removing the hand holding the lever handle in the closed position and would expose the operator to the risks of the handle flying open suddenly and unexpectedly.
U.S. Pat. No. 5,070,582 discloses an integral locking mechanism with counter-rotating gears. This invention comprises a pair of major gear members in engageable connection with a pair of minor gear members attached to a first coupler tension member. A tension connector pin is journaled to both the major gear members and one end of a second coupler tension member. The rotation of the connector pin about the axis of rotation of the major gear members causes the connector pin axis of rotation to be offset relative to the major gear axis of rotation, locking the load binder tool in the closed position. To release the chain, the lever handle is pushed to the open position and the lifting force detaches the handle from the pin. This invention does not provide adequate protection from a premature lever handle release that may subject the operator to injury. With enough force, the handle could disengage from the pin and fly open unexpectedly.
U.S. Pat. No. 4,058,291 discloses a tool for use in securing a chain-type hold-down element. The tool has a tunneled main body portion, through which the chain travels. An opening in the tunnel wall admits a lever that rocks pivotally to the body portion to drive the chain through the tunnel by alternatively engaging and disengaging with it. A fork-shaped component attached to the lever prevents the chain from slipping backwards once it has been tightened. The forked component is lowered down onto the chain and fits through a link to hold it in place. To release the chain, the operator lifts the lever handle, removing the fork from the chain. This invention is inferior to the present invention because it lacks a secure method of locking in place to prevent the forked component from accidentally slipping out and releasing the chain.
U.S. Pat. No. 5,429,463 discloses a removable handle for an operating lever of a load binder for use with a chain hold-down element. The chain is tightened with a toggle linkage and when the lever passes the over-center position, the handle automatically disengages from the lever. The handle is reattached to release the tension on the chain and automatically disengages again when the lever is pushed back past the over-center position. In this manner the operator can theoretically maneuver the lever handle without injury. This invention is inferior to the present invention where it does not disclose a method of securing the lever in place so that the chain is not released prematurely. Additionally, a detachable handle is easily lost or misplaced, detracting from the usefulness of this invention.
The inventions cited here have various advantages and disadvantages with regard to securing load binders, but none combine ease of operability with a high level of assurance against accidental or premature release of the lever handle. Therefore, what is needed is a load binder that provides reliable protection against premature release of the load binder lever handle and is also easy to operate. What is further needed is a load binder that has a locking structure for securing the binder""s lever handle in the closed position. What is still further needed is a load binder with a locking structure that is easy to use and which can be easily secured with one hand, leaving the other hand free to hold the handle in place.
Load binders place the hold-down elements of a transport vehicle under considerable pressure. Loads that shift during transport may add more strain on a hold-down element. When pressure from a load binder is released, either on purpose or accidentally, the hold-down element has a tendency to give way quickly and with great force. This may cause the load binder lever handle to fly open, possibly causing injury to the operator or property and other persons nearby. If the vehicle is underway, an unexpected release of the lever may cause the load to fall, placing the operator of the transport vehicle and others in the vicinity in danger of suffering personal injury and property damage. The falling cargo itself may also sustain damage.
It is the objective of the present invention to provide a load binder with a locking structure that reduces the occurrence of premature release of the pressure applied to hold-down elements by the load binder. It is another objective of the present invention to provide a load binder with a locking structure that is designed to ensure the corresponding locking part will stay firmly in place until the operator desires to remove it. It is yet another objective of the present invention to provide a load binder with a locking structure that does not require a padlock, key, or other additional detached locking part to unlock the binder. It is still another object of the present invention to provide a superior locking structure to secure the handle of overc-enter lever type load binders in order to prevent injury and damage resulting from premature release of the handle.
The present invention achieves these and other objectives by providing a locking structure with two uniquely shaped apertures and a corresponding locking pin. The structure is an extension of either the lever handle or receiving cradle of a load binder. Each aperture is an opening in a flange connected to either the handle or the cradle. The apertures are shaped such that a small portion of the opening is eccentric to the center axis of the aperture. This eccentric portion may be designed with round edges or right angles. The eccentric portion of the apertures are offset from each other relative to the center axis of the aperture, such that upon looking through one aperture, the eccentric portion of the opposite aperture would appear offset from the eccentric portion of the first aperture.
The locking pin is shaped such that a portion of the pin fits through the eccentric portion of the apertures described above in a mating alignment. In the preferred embodiment, the locking pin has one or more extensions shaped to correspond with the shape of the apertures. The pin has two distinct ends. The first end that fits through both apertures is shaped so that it passes through the apertures and their eccentric portions. The second and opposite end is larger than the apertures so that it will not pass through them. In the preferred embodiment, this larger end is formed such that it is easy to grasp and maneuver. The locking pin may be equipped with a spring attachment to provide a biased resistance of the first end against the nearest flange when the pin is in the securing position. One or both flanges may also be equipped with a small recess or protrusion for the first end of the locking pin locking pin to fit into or over to provide further assurance for holding the pin in place. Optionally, to keep the locking pin in close proportion to the flanges of the load binder for ready use, any of the well-known methods for tethering one part to another may be used, for example a wire or chain.
To secure cargo with a load binder, the operator makes the hold-down element taut by maneuvering the lever handle past the over-center point to a fully closed position. With one hand on the handle to hold it in place for securing, the operator grasps the pin attached to the load binder with his or her free hand. The pin is lined up to fit through the first aperture, rotated to fit through the second aperture, and rotated a final time to lock it in place. The pin extends over the handle where the flanges are part of the receiving cradle, or under the cradle where the flanges are part of the handle. In this manner, the pin secures the handle and prevents it from flying open. The special shape of the pin and the fact that it must be rotated to pass through two separate apertures assures that it will stay in place until the operator intends to remove it. When the operator desires to release the load binder, he or she will simply hold down on the handle as they remove the pin, rotating in reverse order to pass it back through the apertures.
These specially shaped apertures and pin are an improvement over prior methods for locking load binders where they offer additional protection against premature release of the load binder lever handle. The rotation of the pin to prevent it from sliding back through the apertures will prevent accidental release of the load binder lever handle controlling the hold-down element. The present invention is also an improvement where it is easily operated with one hand and the pin is attached to the load binder to prevent breakage or loss.
The present invention is designed for load binders already in use and those that may be developed. As an add-on kit for improving existing load binders, the present invention is simple to attach. The flanges can be easily spot-welded to either the lever handle or receiving cradle of a load binder. The pin could be tethered to one flange. Further objects and advantages of this invention will be made apparent in the following description, references being made to the accompanying drawings illustrating the preferred embodiment of the invention.